1. Technical Field
The present invention relates to an image forming apparatus for forming images. The apparatus includes a transfer roller that has a groove portion in which a holder member for holding a transfer material is provided. The transfer roller is pressed onto a carrier that carries images.
2. Related Art
In wet-type image forming apparatuses using liquid developer, a transfer material tends to stick onto an intermediate transfer member after transfer of toner images. This is because the transfer surface of the transfer material such as paper is pressed onto the intermediate transfer member. The transfer surface of the transfer material is a surface on which toner images are transferred. Accordingly, such an image forming apparatus has been proposed that is adapted to remove a transfer material from a transfer roller by blowing air to a tip end of the transfer material, after transfer (see, for example, Japanese Patent No. 3128067).
Besides this apparatus, another image forming apparatus using a dry developer has been proposed (see, for example, JP-A-3-4241). This apparatus is adapted to transfer a toner image on a photosensitive member onto a transfer material while gripping a tip end portion of the transfer material using a gripper. The gripper is included in a transfer drum that is pressed onto the photosensitive member. Gripping the tip end portion of the transfer material during the transfer process allows the transfer material to be smoothly removed from the photosensitive member after the transfer.
However, the image forming apparatus disclosed in Japanese Patent No. 3128067 may fail to remove the transfer material successfully since the apparatus is adapted to merely blow the air to the tip end portion of the transfer material.
Thus, the technology for removing a transfer material by gripping the tip end portion of the transfer material using the gripper disclosed in JP-A-3-4241 may be applied to the image forming apparatus using the liquid developer that is disclosed in Japanese Patent No. 3128067. However, the gripper, which is a holder member used for holding the transfer material, continuously moves during the transfer operation since the gripper is included in the transfer drum and rotates integrally therewith. Therefore, it is difficult to appropriately and stably hold the transfer material being transported to the transfer drum by the holder member at a predetermined position of the transfer material. Further, in JP-A-3-4241, ways of holding the transfer material appropriately and stably at a predetermined position by the holder member that continuously moves in the image forming apparatus are not disclosed.
Thus, it is difficult to successfully perform image formation with a combination of the technology for removing the transfer material disclosed in JP-A-3-4241 and the image forming apparatus disclosed in Japanese Patent No. 3128067.